The product of 4.8 and the sum of 2 and a number

Determine the quotient and remainder when (6a3)+11a2-4a-9) is divided by (3a-2) express your answer in the form q(a) + r(a)/d(a)

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?